Translating device



July 21, 1931. J. 5. HIGH THANSLATING DEVICE File i June 13, 1929 3Sheets-Sheet 1 INVENTOR 3/0 19 6. High.

ATT'Q NEY July'2l, 1931. J. 5. HIGH 1 THANSLATING DEVICE Filed June 13,1929 3 SheetsSheet 2 VINVENTOR Jizrj isni Hjg'h.

ATTORNEY July 21, 1931. J. 5. HIGH I TRANSLA'I'INQ DEVICE Filed June 15,1929 3 Sheets-Sheet 5 INVENTOR \fi/rjen 5. High.

ATTORNEY Patented July 21, 1931 p UNITED S E PATENT OFFICE JURJEN s.HIGH, o wnxmsnme, PnNNsYLvANIA, AssIGNoR TO WESTINGHOUSE ELECTRIC &MANUFACTURINGCOMPANY, A oonronATIoN or PENNSYLVANIA Q'raANsLArn einEvIoEApplication filed. June 13,

My invention relates to devices, such as microphones and loud speakers,for translat ing between electrical energy and. sound energy. V y a i iii It is an objectofm'y invention to produce a translating deviceinwhichythe diaphragm shall be provided, throughout its area, with 'meansfor effecting energy translation. Whenthe device i sa loud speaker, theforce exerted by the electro-dynamic. forces 'is exerted at. many pointsdistributed over the diaphragm. Likewise, when the device is acting as amicrophone, the diaphragm being moved bythe sound pressure, the resist-,ance to the motion presented by theelectrodynamic'forces isexertedatnumerous points distributed over thediaphragm.

In that form of my invention in which the diaphragm is freeto move as aWllOlQthiS distribution results inia plunger-like movement of thediaphragmg On the other hand, when the diaphragm is restrained alongcertain lines or at certain'points, the intervening portions vibrateelfeotively, notwithstandingsuch restraint, because of the distributedforces.

his a further object omyinventionto provide a means forproducing fluxthrough thediaphragm overa very considerable area thereof withoutcausing'the inagneticstrum ture tohinder the passageof soundto or fromthe diaphragm. It is a further object of my inventlon to provide acurrent-carrying conductor which shallbe the electricalequivalent oftwdflat closely adjacent current sheetswithwthei'r currents in oppositedirections. i

It is a further object of my invention to sodistribute the magnetic fluxthatit shall co 40 operate with substantiallyrthe whole ofeach of saidcurrent sheets. i i

I have found. it desirable to space apart the individual pole-memberswhichcollectively constitute the means fordelivering the 4 flux tocooperatewith: said current sheets. I havelikewise foundit. desirabletospace 1 apart the" conductors which -carry the cur.-

rent, heretofore described as current sheets.

It isa further object of my invention toso 0 locate the individualpole-members'that near:

larg'ed scale, partly in section,

posite polarity.

1929. Serial No. 370,526.

lyall of the flux will traverse the plane of the double-current sheetinthose parts of the plane occupiedby the conductors and in such directionthat the resultant mechanical force will be effective.

It is afurth'er object of my inventionto provide a-means wherebyrattling noiseswill be prevented, thereby enabling paper, or other sheetmaterial liable to produce such noises. to serve acceptably as the bodyof the diaphragm. i

A sheet ofmaterial of only slight stiffness, such as thin paper, canremain ina vertical position without buckling or otherwise collapsing,provided it is supported on each side against tipping or anylargebending movement. It is another object of this in- .vention'to takeadvantage of this property of such sheet material.

Details of .thestructure: and further objects of my invention will bereadily understood from the following description and the accompanyingdrawings, in which Figure'l is a perspective view showing the devicewith parts broken away,

Fig. 2is a rear elevation of the apparatus shown in Fig. 1,

Fig. 3 is a section ontheline IIIIII of Fig.2, j, 3

view of a support on an en- Fig. 5 is a vertical section, on an enlargedscale, through a portion of the diaphragm and the adjacent individualpole-members, and

is aside elevational View of the diaphragm. F i

The device is housed in a casing 1 open at 'the front 2 andback 3. Acoil 4 surrounds the central member 5 ofthe magneticcircuit. Thewindingof the coil lis intended to carry directcurrent, whereby all ofthe polar uprights 6, at one side of the coil, are of the same polarity,and all of the polar uprights 7, on theother side ofthe coil,are of theop- Blocks or bars 8, preferably of non-magnetic material, space themagnetic circuit away from the floor of thecasing and provide therebysufiicient room for the coil 4. i y The uprightpole-pieces] are providedwith aligned grooves 9traverse to the faces of the pole-pieces 7 whichare toward the I pole-pieces 6,:and the pole pieces 6 are traversed byaligned grooves 10 on the faces thereof toward the pole-pieces 7. Thegrooves 10 are staggered relative to the grooves 9. Individualpole-members '11, of

sufficient length to'extend across the whole collection of pole-pieces7, grooves 9 with a press fit.

If preferred, the joints betweenthe shelf like individual pole-pieceslland the poleare fitted in the pieces 7 may be welded, the junction beingsuch as to present the smallest possible mag. netic reluctance in thejoints.

shelf-like extensions or individual pole Similarly,

the individual pole-pieces 1'2, and the free the'seats of'the severalmagnetic poles, are

sheet and ribbon, whereby edges of the individual pole pieces, which arein staggered relation, asshown in Fig. 3, and more clearly in: Fig. 5.

The diaphragm is located between the individual"pole-pieces 1 1 and 12'.It con1- prisesa sheet 16 of drawingpaper or other sheet material uponwhich apribbon 1-7 of aluminum or. other conductive material is wound.The ribbon 1? extends the full length 1 of the sheet 16 and, at'theedge, is folded, as

shown at 18, to extend in the reverse direc tion the full length of theother side of the sheet.

Adjacent to the fold18, the ribbon is cleflected laterally, as shownat19, and a similar deflection occurs on the other face of the of thetwodeflections,isvsuflicient to locate each length of ribbon upon thereverse side of the sheet, midwaybetweentwo adjacent lengths of ribbonupon the obverse side of thesheet. Thus, the length 22 on the obverseside ofthe sheet, asshown in Fig. 6, is mid way between two lengths 23upon the reverse sideof the sheet. Preferably, the width of the ribbonis approximately equal to the width of the spaceb'etween each length andthe neighboring length on the opposite: face of,

the sheet.- i r V Anydesired way of securing the ribbon to the sheet maybe "employed.- Itm'ay be cemerrted; the metal may be forced into theinterstices between the fibres of thesheet by pressure; the combinedsurface of ribbon and sheetmaylbe varnished, or any other way'o-finsuring that the sheet and ribbonwillmove as a unitary structure may beemployed.

Preferably, the assemblage,- comprising is subjected to pressure, thepaper-is slightly deformed into a zigzagshape, as illustrated at 24 inFig. 5. As a consequence of this deformation, the successive lengths ofribbon are nearly in one movementamong themselves and are of relativelysmall density, will serve the purpose. Very soft loose cotton felt mayserveJ The silk or other fabric 26 may be supported in placebybeingfolded across the upper edge of the diaphragm, as shown at 30 inFig. 4. Any other suitable means for 'supportlng the fabric in placemaybe used, but the fabric nee'd not be cemented to the faces of the diaphragm.

' In oneform of my invention a part only of the space between thediaphragm: and the ends of theindividual' pole-membersis occup-iedbytheuncompressed volume of the silk.- Theunoccupiedportion of the spacebetween the diaphragm: and the ends-of the'magnetic' structure isintended to be sufficient toaccommodatethe normal movements of thediaphragm; Thesilk will not be compressed b etween the diaphragm and thePOlBflDlECe in traordinary excursions of the diaphragm 7 occur. r

In an alternative form, the fabric is made to fill loosely the. spacebetween the chaphragm 15 and the edges of the pole-member's -11 and 12.Motion of the diaphragm in this form is largely restricted to theportions between pole pieces. The upper edge of the diaphragnmtogetherwith the folded edgeof thesilk, is thrust r between two pieces. of softfelt 31, the upper sheet, as shown, at 20. The combined effect portionof the adjacent faces of which are glued together. The joined pieces offelt may form a frame extending aboutthe whole periphery of thediaphragm or felt maybe 1 used only at certain points, for example, at cthe corners thereof. At 32 in Fi'g. 1, several separated portions of thefelt are shown and in Fig. 2, the complete frame of felt is illustrated.Atjthe top" of the diaphragm, the felt, by loosely engaging the topplate 33 of the casing, permits transverse displacement of thediaphragm.

At the bottom of'the diaphragm, similar contact between the felt and aplate '34 of brass or other nonmagnetic sheet material permitstransverse movement of 1the diaphragm,

The plate-34 supports the diaphragm,

while the ends of-the pole-members prevent 'it from falling by tippingorbuclrling. The top plate83, of the casing, being fastened to. theu-pright pole pieces 6 and 7, takes the thrust set up the magneticattraction between pole membersll' and 12. l

ran

The diaphragm structure includes, beside tional flux betweenthe]individual polepieces, as indicated in Fig."5.c i

The terminals of the ribbon 17 ,shown extending toward the left'in Fig.6, are con.- nected to a source of audio frequency cur} rent, inthe'case of a loud speakeiy or to deliver the current producedwhen thedevice is acting as a microphone. c

Inthe loud-speaker act on, current flows in the aluminum ribbon.Considering the moment at which the direction of the current is into thepaper in the lower length 23 of the conductor, as illustrated inFig. 5,the

"direction of the current isup from'the paper.

inthe length 22 of the conductor in Fig. 5

i If'the right-handindividual pole pieces in Fig. 5 be regarded as north.poles,the lefthand ones will beregarded. as'south poles. The resultingthrust upon the length 23 of the conductor shown atthe bottom of Fig. 5

willqbe upward andto the right At this moment, the force exerted ontheiconductor 22 is downward and to the right. The stifi ness of thediaphragm structure is sufficient .to prevent' the upwardfomponent ofthe force upon the lower length 23 oftheconductor and the downwardcomponent of the force upon the adjacent conductor 22 from producing anyresult, but thetwocompo 'nents of these twoforcestoward the right 7,cause a movement of the diaphragm in that direction.

upon each length of the conductor will show that, over the whole surfacecoverediby the winding, thereis, at the moment under consideration, auniformly distributed force toward the right. This forcegisuniformlydistributed in the sense that it isfequaljover many pointssystematicallydistributed in a uniform fashion over the area of thediaphragm. It is not meant to assert that the -.force betweentwoadjacentlengthsof conductor is equal to that at the conduct themselves.l I

' In the form of the device in which there is suificient spaceprovidedbetween thedia phragm and the pole-members, the diaphragm moveslaterally without flexing. It

produces a plunger-like action faithfully representingthe wave-form ofthe current deliveredto the winding. Any tendency for vibration byflexing, with a consequent rat-.

tling noise, is prevented by iion of the silk.

In the alternative form in the I damping acwhich the edges of thepole-members are close to the silk, latc c c a u "struction willreadilyoccurto those skilled A similar examination of the forces actingeral movement of the corresponding parts of the diaphragm is preventedor partially prevented and the diaphragm vibrates in a sysdiaphragm isprevented from interfering with that from the other face by thesidewall. and" top 33 of the casing and the plate .32. Together, theseconstitute a frame surrounding the diaphragm, which has much 1 the sameresult as a baffle-board. This frame must not be too will result.

When the device is acting as a microphone, thesound pressure causes thediaphragm to move with a plunger-like motion. Each condeep or abanel-like effect ductor length moves across its respective flux at thesame angle and the electromotive forces induced in each add, with theresult that theelectromotive force produced at T amount. e e p Both inthe loud-speaker action of the dethe terminals of the winding 17 is of auseful vice and in its microphone action, it will be seenthat the soundreaches the diaphragm through openings providedby expanding the metallicstructure of the magnetic circuit into alatticework. It will also beseen that, in

I both cases, the movement of the conductors is at an angleapproximately45 to the direc-v This is an advantageous angle thatcan beobtained with a flat surface and a distributed pole-piece structure.

Many variations ofthe details of the conin the art. The omission of anyspecific mention of such variations is not intended as" a limitation.The only intended limitations arefthose required by theprior art andexpressed in the claims.

I claim asmy invention:

In a translating device for electri'cand acoustic 'energy,a sheet, awind ng dlstributed over both faces of said. sheet andiiuX-producthroughout the major partthereof.

uted over both faces of said sheet and means mo located :onboth sides ofsaid sheet for pro- .ducing-pflux through said sheet to cooperate withsaid winding.

3. In translating device for electric and ing pole-members spaced fromone another and the pole-members on one pole-piece being mgimeanscooperating with, said winding acoustic energy, a magnetic circuitcompris- 1 ing oppositely located pole-pieces, each pole 1 piece havinga plurality of parallel-projectopposite the spaces between the pole-memiin bers on the other pole-piece, whereby the pole.- members are instaggered relation.

acoustic energy, a magnetic circuit comprising a pair of sets ofpole-pieces, the sets being located in opposed relation and themembersof each setjbeing spaced apart, an open work of magnetic materialextending from one set of pole-pieces toward the other, a similar openWork extending from the other set of pole pieces toward the first,whereby the adjacent extremities of the open work are on opposite sidesof an air gap. j V j i 5. In a translating device for electric andacoustic energy,a magnetic circuit comprising a pair of sets ofpole-pieces, the .sets

I being l-ocatedinopposed relationand the members of each set beingspaced apart, an

' open work of magnetic material extending area COIIIPIlSlIlg anopen-Work of magnetic from one set of pole-pieces toward the other', a

similar open work extending from the other. set of pale pieces towardthe first, whereby the "adjacent extremities of the open work are onopposite sides of an air gap and the individual pole-members of one openwork are opposite the open spaces of the other, whereby the terminals ofthe magnetic circuit are in staggered relation. 1: 1

6. In a translating device for electric and acoustic energy, a diaphragmanda magnetic circuit includingportions adjacent to said diaphragm onopposite sides thereof, said portions being of lattice work wherebysound may readily pass therethrough. n

7. A structure for conveying flux to an material extending oversubstantially all of said area and afl'ording passage extending from theexterior of said structure to regions distributed over substantially allof saidarea.

8. In a translating device for electric. and

V acoustic energy, a sheet, a plurality'ofconductors secured on saidsheet and meansfor producinga magnetic flux across each of saidconductors at an oblique angle to said'sheet.

9. In a translating device for electric and acoustic energy, a pluralityof magnetic pole- "members located on opposite sidesofa plane,

a windingv and means for supporting the Winding approximately in saidplane. I V

10. In a translating device for electric and acoustic energy, aplurality of magnetic pole--members located in staggered relation onopposite sides. of a plane, those on one side being all of one polarityand those on the other side being all of the oppositepolarlty,

. a winding and means for supporting the winding approximately in saidplane; 7 11. In a translating device for electric and acoustic energy, aplurality of magnetic polemembers located in staggered relation onopposite sides of a plane, those on one side being all of one polarityand those on the other side between the clasea proximately in said planewith the individt ual turns thereof approximately midway 4:. translatingdevice for electric and including pole-structures extending over a majorportion of the area of the diaphragm on each side thereof and dampingmaterial pole-structure and the diaphragm, 1

l3. In a translating device for electric and acoustic energy, a magneticcircuit connecting the sidesof an air gap and a diaphragm neticcircuitbeing concentrated and the pole portions being. of open workwhereby the;

cross-sectional area eifective to carry the flux carried by the midportion is distributed at the pole portions over an area approximatelythat of the diaphragm.

14:. In a translating device for electric and acoustic energy, adiaphragm, means for exertingv force transverse to the diaphragm atplaces distributed over amajor. part of the area thereof and dampingmeans covering substantially all of said part.

15'. 1111a translatingdevice for electric and acoustic energy, adiaphragm, means forexerting a force transverseto the diaphragm atplaces distributed over a major part of the area thereof and a connectedsheet of material lighter than the material of said diaphragm extendingover. substantially all of said part. a

16. In a translating device for electric and acoustic energy, adiaphragm, means for exerting force transverse to the diaphragm atplaces. distributed over a najorpart. of the area thereof and aconnected sheet ofmaterial lighter than the material of said diaphragmextending overisubstantially all of said part andfree tomove relativethereto.

17. In a translating device for electric and acoustic energy, amagnet-1c circult having an air gapin'theform ofa crevice, adiaphragm insaid gap supported only at parts thereof extending beyond the and "ofsufficient stifi'ness to maintain itself in positionwithin thegap.

. 18. A diaphragm comprising a supporting sheet and a ribbon ofconductive material wound flat on both faces of said sheet.

19. A diaphragm comprising a supporting sheet and a ribbon of conductivematerial wound flat on both faces of said sheet and forming therewith astructure of suificient stiffness .to support itself against bucklingwhen placed in a vertical plane.

. In testimony'whereof, Ihave hereunto subscribed my name this 31st .dayof May, 1929.

being allof the opposite polarity, a winding j in said air gap, the midportion of said mag- 9

